When optically scanning the sample with the scanning microscope, at a given moment only a selected point or line region of the sample is optically scanned. For this purpose a focusing lens system of the microscope focuses an illuminating light beam of the microscope on the selected region of the sample and detects the proportion of light that is sent back from the selected region, for example as a result of fluorescence effects in the sample. The image data obtained are stored. Then, other point or line-shaped regions are investigated which are preferably adjacent to one another and form, for example, a line or an area. In this way a large area of the sample can be optically scanned point-by-point and line-by-line. The data of the individual points are then compiled by means of a data processing apparatus to give an overall picture of the region of the sample that has been examined.
In order to guide the illuminating light beam onto the individual selected regions, it is known to direct the illuminating light beam in the microscope through a scanning device having a plurality of reflectors. The reflectors are each coupled to one or more actuators. Triggering the actuators causes the reflectors to be adjusted, thereby deflecting the illuminating light beam. After passing through the focusing lens system the deflected illuminating light beam hits the correspondingly selected regions of the sample.
Scanning microscopes of this kind are widely known and are basically very expensive because of their complicated construction. The image quality is crucially determined by the quality of the lens system of the microscope. This must have good imaging properties, for example colour correction, for all the scan angles that occur.
A device for deflecting a light beam and a scanning microscope are known from DE 102 09 322 A1. The device for deflecting the light beam has a unit that is rotatably about a first axis, comprising two reflective surfaces which are fixed relative to one another and receives a light beam and transmits it to a third reflective surface which is rotatable about a second axis extending perpendicularly to the first rotational axis. The rotatable unit has a further reflective surface which is fixed relative to the first and second reflective surfaces, the first and further reflective surfaces being arranged perpendicular to the second reflective surface.
From DE 100 33 549 A1 an optical arrangement for deflecting a light beam in two directions substantially perpendicular to one another is known. The arrangement has two reflectors which are each rotatable by means of a rotary drive about axes that are perpendicular to one another. An additional reflector in a prescribed angular position is non-rotationally associated with one of the reflectors.
DE 10 2004 042 913 A1 describes a device for scanning an object in which a carriage drive moves an objective lens in synchronism with an object support. During the movement of the object support optical scanning takes place.
It is known from DE 101 52 609 A1 to move an objective of a scanning microscope transversely with respect to the optical axis. There is no movement transversely with respect to the direction of an illuminating light beam providing direct illumination.
In the known confocal microscopes, a plurality of lenses and complicated objectives are used. An illuminating light beam is scanned over the sample by means of reflectors coupled to galvanometrically operating control elements. Alternatively, the lens-free optical near-field microscopy is also known. In this, an extremely sharp point is needed which is guided over the sample at a sub-wavelength distance and provides information only regarding the surface.